Carbon feeding and adjusting mechanism for arc lamps



NMA 2% 3.927. 1,5094@ W. G. PREDDEY i CARBON FEEDING AND ADJUSTING MECHANISM FOR ARC LAMPS Filed- Feb, l, 1926 WHHIWHM.

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mum W. G. PREDDEY CARBON FEEDING AND ADJUSTING MECHANISM FOR ARC LAMPS Filed Feb. l. 1926 2 Sheets-Sheet 2 Patented New @9 lQZ'FQ .WALTER G. JREDDEY, 0F SAN ERANCSCG, CALEFORNEA.

Application led 'February l, 1926. `Serial No. 85,231.

My invention relates to improvements in mechanism for feeding and adjusting the carbons of arc lamps and the like whereby a pair of carbon electrodes are adjusted and' maintained in arc producing relation.

rlhe primary object of my invention is to provide an improved carbon 'feeding and adjusting mechanism for arc lamps.

Another object is to provide an improved mechanism adapted to facilitate the initial adjusting of carbons andfto facilitate and obtain a saving in timein changing carbons and in resetting the carbon carriers of an are lamp.

A still further object is to provide an improved power actuated feeding mechanism adapted to be normally operated by an electric motor whereby power may be positively applied to move the carbons simultaneously7 at a very slow speed to maintain the correct relation of the carbons to produce an ecient arc. I I

A still further object is to provide an improved device ofthe character described adapted to be operated either manually or by power and adapted for quick manual adjustment.

A further object is to provide an imj y proved construction wherein a power feeding mechanism isadapted to obtain avery great reduction of speed within a mlnimum of space..

A still further object is to provide an improved device of simplified construction which will be highly efficient in operation and which will 'facilitate the care and adjustment of the lamp.

l accomplish these and other objects by means of the improved device disclosed in the drawings forming a part of the present specification wherein like characters of reference are used to designate similar parts throughout said specification and drawings and in which,

Fig. l is a side elevation of my improved carbon feeding and adjusting mechanism.

y lig. 2 is a plan view of the devicel as disclosed in Fig. 1 of the drawings.

Fig. 3 is a front elevation, partly in section, of a carrier and shaft engaging means.

Fig. 4 is a side elevation of the carrier as shown in Fig. 3

Fig. 5 is a broken front elevation of the shaft rotating mechanism.

Fig' is a plan view of the mechanism shown in Fig. 5.'

Referring to the drawings the numeral l is used to designate in general the frame of an are lamp of the character used in the projection of motion pictures and the like. A pair of shafts 2 and 3 are rotatably mounted upon the frame l, said shafts extending longitudinally across the frame l and eX- tending outwardly from one end thereof.

rlf'he shaft 2 is provided with right and left hand threaded portions extending inwardly from the ends to substantially the middle of the frame7 said threaded portions being arranged to be engaged in a manner hereinafter more fully explained by a pair of carriers l each arranged .to receive an arc carbon 6, said carbons being held in axial alignment to produce an arc in the well known manner. rlhe carriers d extend transversely across the frame l and are mounted in slidable engagement with the shaft 3..

'llhe shaft 3 is threaded along the middle portion thereof, said threaded portion being engaged by a carrier 7 arranged to support a redactor 9 for projecting light from the arc produced between the carbons 6, said carrier being arrange-d to be moved longitudinally along the shaft by an appropriate rotation of said shaft. A knob 9 is provided upon the outwardly extending end of the shaft 3 whereby the shaft may be manually rotated to adjust the longitudinal position of the reector relative to the carbons 6.

The carriers d are provided with bushings ll slidably engaging the shaft 2 and movable freely over the threads thereon. llhevers 12 are pivotally mounted upon the under sides of the carriers, said levers being movable in "slots 1? to engage the threads of the shaft 2. The levers are arranged at an angle equal to the pitch of the threads and are normally held in engagement with said threads by means of suitable springs le whereby a rotation .of the shaft will cause the carriers to be moved longitudinally therealong. 'Handles 16 are formed upon the outer ends of the levers l2, said handles extending outwardly whereby the levers mayi be pressed downwardly out of engagement 2 renonce with the threads, thereby permitting the carriers to be moved freely along the shaft in either direction independently of the rotation of the shaft 2, as shown in Figs. 3 and Il of the drawings.

rllhe shaft 2 is arranged to be rotated by power derived from a suitable electric motor l? mounted upon the frame 1 and arranged to be energized and controlled by the flow of electric current through the arc whereby said motor may be operated to automatically rotate the shaft and move the carriers l in proportion to the consumption of the carn bons 6, in a manner well known in the art f and requiring no particular description herein. .Power is imparted from the motor to the shaft 2 by means' of a worm 13 secured" upon the shaft of the motor and arranged to mesh with a worm gear 19 'rot-at ably mounted upon a sleeve 2l which in turn is rotatably mounted upon the outwardly extending end of the shaft 2. The sleeve 21 abuts against a collar 22 secured upon the shaft 2. A ratchet 23 is rotatably mounted upon the shaft and arranged to abut against theopposite end of the sleeve 21, said ratchet being held in frictional engagement with the sleeve by means of a suitable spring`2d compressed between the ratchet and a collar 26 secured upon the shaft 2, the pressure imparted by the spring 24 being sufficient to hold the ratchet in driving relation to the sleeve whereby a rotation of the ratchet will cause a corresponding rotation of the sleeve which is in turn imparted tothe shaft 2 through the collar 22.

A cam 27 is connected to the worm gear 19 between said gear and the ratchet 23. A lever 28 is pivotally mounted as at 29 and arranged to rest upon the cam 27, the eccentricity of the cam being arranged to oscillate the lever 28 through a desired degree of movement when the gear 19 is rotated by the motor 17. A pawl 30 is pivotally mounted upon the lever 28 adjacent the ratchet 23, said pawl being arranged to engage the ratchet teeth 31 of said ratchet. The throw of the lever 28 and pawl 30 is arranged to cause the ratchet to be moved through a distance equal to the length of one tooth 31 for each revolution of the worm gear 19, the lever being lifted upwardly by the cam 27 to impart as positive driving force to the ratchet as shown in Fig. 5 of the drawings. i

The shaft 2 eXtends'outwardly past the ratchet 23' and is provided with a knob 32 whereby the shaft may be manually turned independently of the/power actuating con-` upon the carriers l in any suitable manner, and adjusted to bring the adjacent ends into the desired proximity. As the cai-bons are consumed the motor, controlled by the flow of current forming the arc between the carbons, is energized and caused to rotate the shaft 2 very slowly, thereby causing the carriers to be advanced toward each other by means of the right and left hand threads formed thereon. The driving connections above described alliords a ver 1 creat reduc- "V tion of speed, a great reduction being obtained through the worm 1 3 and gear 19. A single full rotation of the gear 19 operates to move the ratchet only through the length of one tooth and as a result the movement of the carriers along the shaft 2 a most imperceptible even when the motor is operating at normal speed. The cam and ratchet mechanism perits this very great reduction of speed to be obtained in a very small space and with relatively few parts, thus obtaining a compact, economical and highly efficient mechanism. The shaft 2 1s rotatable by means of the knob 32 independ-- effects a big saving in time to the operator.

llt is essential that the interruption neces sary to accomplish the resetting of the carbons be kept at a minimum and the saving effected by my improved device is therefore of material advantage.

Should the carriers be inadvertently advanced to their extreme positions, my improved driving connection permits the rotation of the gear and ratchet to be con 'ardless of whether llG tinued without injury to any portion of the device, the frictional drive between the ratchet and shaft preventing damage to the motor or moving parts of the mechanism.

While I have illustrated and described what I now regard as the preferred form and construction of my invention, the specific details of construction are of course subject to modiiication in various ways. I therefore do not Wish to restrict myself to the specific form and construction illustrated and described, but wish to avail myself of all modications which may fall within the scope of the appendedclaims.

Having thus described my invention what i I claim as new and; desire to secure by Letters yPatent is,

Y moved longitudinally therealong by a ro lll tation of the shaft; and means for rotating said shaft, said means comprising a power driven worm gear rotatably mounted upon the shaft; a ratchet frictionally engaging the shaft; means connected between the gear and the ratchet for' actuating said ratchet to rotate the shaft at a greatly reduced speed whereby the carriers may be moved to maintain carbons carried thereby in correct relation.

2. fn a carbon arc lamp;fa threaded shaft; a pair of carbon carriers mounted in connection with said shaft and arranged to be moved longitudinally therealong by a rotation of the shaft; and means for rotating said shaft, said means comprising a power driven worm gear rotatably mounted upon the shaft; a ratchet frictionally engaging the shaft; means connected between the gear and the ratchet for actuating said ratchet to rotate the shaft at a greatly reduced speed whereby the carriers may be moved to maintain earbons carried thereby in correct rela-fV tion; and means for disengaging the carriers from the shaft, to permit the independent adjustment of said carriers along the shaft.

3. ln a carbon arc lamp; a threaded shaft; a pair of carbon carriers mounted in connection with said shaft and arranged to be moved longitudinally therealong by a rota- Ytion of the shaft to adjust the relation of a pair of carbons carried by the carriers; and means for rotating said shaft, said means comprising a power driven worm gear rotatably mounted upon the shaft; a ratchet frictionally engaging the shaft; a'cam connected to the gear; a lever pivotally mounted adjacent the cam; and a pawl pivotally mounted upon the lever and arranged to engage the ratchet; said lever being arranged to be oscillated by the rcam whereby the pawl may be actuated to rotate the ratchet and shaft.

4L. lln a carbon varc lamp, a threaded shaft; a pair of carbon carriers mounted in connection with said shaft and arranged to he moved longitudinally therealong yby a rotation of the shaft to adjust the relation of a pair of carbone carried by said carriers; and means for rotating said shaft, said means comprising a sleeve secured upon one end of the shaft; a power driven worm gear rotatably mounted upon the sleeve; a ratchet rotatably mounted Fupon the shaft adjacent one end of the sleeve; means for holding the ratchet in frictional engagement with said end of the sleeve rotating said sleeve and shaft; a cam connected to the gear; a lever pivotally mounted adjacent thel cam; a pawl pivotally mounted upon the lever and arranged to engage the ratchet,

said lever being arranged to be oscillated by the cam whereby the pawl may be actuated to rotate the ratchet and shaft.

5. lfn a carbon arc lamp, a threaded shaft; a pair of carbon carriers mounted in connection with said shaft and arranged to be moved longitudinally therealong by a rotation of the shaft to adjust the relation of a pair of carbons carried by said carriers; and means for rotating said shaft, said means comprising a sleeve secured upon one end of the shaft; a power driven worm gear rotatably mounted upon the sleeve; a ratchet rotatably mounted upon the shaft adjacent one end of the sleeve; means for holding the ratchet in frictional engagement with p said end of the sleeve forrotating 'said .sleeve and shaft; a cam connected to the gear; a lever-pivotally mounted adjacent the cam; a pawl pivotally mounted upon the lever and arranged to engage the ratchet, said lever being arranged to be oscillated by the cam whereby the pawl may be actuated to rotate the ratchet and shaft; and means for rotating the shaft independently of the gear and ratchet- ,6. lin a carbon arc lamp; a threaded shaft; a pair of carbon carriers mounted in connection with said shaft and arranged to be moved longitudinally therealong by a rotation of the shaft to adjust the relation of al pair of carbons Acarried by said carriers; and means for rotating said shaft, said means comprising a sleeve securedupon one end of the shaft; a power driven worm gear rotatably mounted upon the sleeve; a ratchet rotatably mounted upon the shaft adjacent one end ofthe sleeve; means for holding the ratchet in frictional engagement with said end of the sleeve for rotating said sleeve and shaft; -a cam connected to the gear; a"

lever pivotally mounted adjacent the cam; a pawl pivotally mounted upon the lever and arranged to engage the ratchet,- said lever being arranged to be oscillated bythe cam whereby the pawlumay be actuated to rotate the ratchet and shaft; and means for rotating `the shaft independently of the gearand ratchet; vand means for disengaging the carriers from the shaft tovpermit the independent adjustment of the carriers along the shaft independentlyvof any rotation thereof. y

7. lin acarbon arc lamp, a threaded shaft, a pair of carbon carriers mounted in association with the shaft; 'a power actuated worm `gear rotatably mounted upon one end of the shaft; a ratchet mounted adjacent the gear; means for holding the ratchet in frictional engagement with the shaft for rotating said shaft; a cam connected tothe gear; a lever pivotally mounted adjacent the' cam; a pawl pivotally mounted upon the lever and arranged torengagle the ratchet, said.- lever be arranged to be oscillated et i,

hy the cane whereloy the pawl may he actuated to rotate the ratchet and shaft; and a iever pivotally mounted upon each carrier and arranO'ed-to enG'ae'e the threads of the' D C D shaft `for moving the carriers relative to the shaft when said shaft is rotated, said levers being inovahle to disengage said threads and `permit independent movement or' either `carrier in either direction independently of the rotation of the shaft.

8. link a carbon are lamp, a threaded shaft; a pair of carhon carriers mounted in assoeiation with the shaft; a power actuated worm gear rotatably mounted upon one end of the shaft; a ratchet mounted adjacent the gear; ineans for holding the ratchet in frietional engagement with the shaft for rotating said shaft; a cane connected to the gear; a lever pivotally mounted adjacent eeoefie the cani; a pawl pivotally mounted upon the lever and arranged to engage the ratchet, said lever loeinp,` arranged to 'he oseiliated hy the Cain whereby the pawl may he actuated to rotate the ratchet and shaft; and a lever pivotally mounted upon each carrier and arranged to engage the threads oi' the sha-ft for rnovingthe carriers relative to the shaft when said shaft is rotated, said levers being movable to disengage said threads and permit independent movement of either oarrier in either direction independently o'f the rotation olf the shaft; and means for nor inally holding the levers in engagement with the threads.

lin witness whereof l hereunto set my signature.

WALTER G. PREDBE. 

